DE 2632243 A1 discloses a printing machine transfer drum that can be adjusted to variable sheet lengths, which has two sheet segments that engage with one another in a meshing fashion, one being connected to a leading-edge gripper system and the other being connected to a trailing-edge sucker system. The disadvantage of this solution is that the length of the individual comb teeth is configured to accommodate the maximum format length, which means that format lengths that are less than half the maximum format length cannot be processed since telescoping of the segments is limited, or the teeth will protrude into the channel.
DE-OS 23 58223 discloses a printing machine transfer drum, which has devices for capturing the leading and trailing edges of sheets, in which the length of the individual comb teeth is configured based on the minimum format length, and extendable or foldable bridging elements are required for processing the maximum format length. The disadvantages of this solution include, on the one hand, that the means (joints, guides) for achieving the necessary precision of the lateral surface (cylindrical shape) are complex to produce, and on the other hand, that either additional drive means are required for unfolding/extension, or if a simple slaving process is used, large clearances or spring forces may be present, which can interfere with format adjustment and with the printing process.
Furthermore, DE 10346782 A1 discloses a sheet transport drum for a machine for processing printing material sheets, in which pneumatic grooves are formed in segment teeth of comb segments. The disadvantage here is that only limited pneumatic force can be applied to certain grooves, and pneumatic force cannot be applied to the sheets over the full width that is required. A device that is effective over the entire sheet width is known from DE 10 2012 218049 A1, however said device is very narrow in the circumferential direction and is thus also limited to a small area. Thus the functional area that is available for the arrangement of pneumatic operating elements is limited in known storage drums.
DE 10 2007 061399 A1 discloses a sheet-guiding drum having a channel bridge that spans a gripper channel.